I have had this happen a number of times, DC says it was delivered but I never received my package. And I was home so they never knocked or anything. I think postal carriers are getting sloppy, especially FED-EX. During Christmas I never left the house because they would leave packages at the door and not even knock. After pestering the post office they found it, but 4 days after they "delivered" it. Good luck, I would probably believe her though.